PRoblems with 1995 GMC Suburban 4x4

[RYANBROWN]

I have a 1995 GMC suburban 4x4 1500. The truck had been sitting for some time and I decided to get her running again. Sprayed carb cleaner in the carb to get it running, ran fine fine for a week and started to have problems with the idle. Revs higher than it should (around 1200 to 1500 RPM's). I managed to get the idle down to where it should be but when the truck is in gear and the engine is under load I can floor it and it will neither rev up or run past the speed of about 10 MPH. ANy ideas on what it could be?

[dave]

A 95 with a CARBURETOR??????????????????????????

[CouchTater]

The carb has 2 electronic fuel injection nozzles.
Carb cleaner was sprayed down in each hole.
This is my vehicle,ryan unfortunately is my nephew.
The suburban ran great for a week,then it started to idle rough.
I checked for vaccum leaks and found none. I adjusted the timing to 800 to 900 rpms, but it still revs high.
When you shift to drive and floor it,it will only go about 10 to 15 mph.
Would the O'2 sensor cause this or the TPS??
Any suggestions??
If I adjust the timing higher,where the engine is really revving between 1200 and 1500 rpm's in park.
When I shift in drive,the vehicle is ready to go,without using the pedal.As I drive down the road,When I get it up to 30 or 40 mph,I can let off the gas pedal and it will cruise at that speed like its in cruise.
I am know mechanic, if I can save a buck with a suggestion,then I will give it a try.
I

[dave]

Ok, not carburetor ... Throttle Body Injection (TBI) EFI.

I think one of the injectors is not spraying fuel? Get the truck running without the air cleaner installed. Look to see if one / both injectors is spraying fuel while the engine is running. I sometimes strobe the timing light at the injectors instead of the timing indicator. Kind of cool trick.

dave

[c_rock]

I think that if it had been sitting for a while, the fuel might be all gummed up. When you had it running for a week it was probably running off what was left of the clean fuel. Then it started sucking the sludge off the bottom of the tank. I would check to see if the injectors are spraying and change out the fuel filter. It could be so badly clogged that there is only enough fuel getting to the TBI to make it run, not enough to make it run well enough to get past 15 mph.

[RYANBROWN]

we put two cans of Sea foam in the tank to take care of any water that may have been in there or dirt fuel components. The injectors in the TB spray just fine and seem to spray even more as it should when you rev the motor. The motor will rev all day long when not in gear, as soon as there is a load on the motor and tranny, you can push the pedal all the way to the floor and get nothing out of it. Im pretty sure that CouchTater (my uncle) replaced the fuel filter when they were getting it running again.